Exposure-associated health implications of potentially toxic elements in maternal and umbilical cord blood at Ishaka adventist hospital, Bushenyi District, Uganda

Abstract

Prenatal exposure to potentially toxic elements (PTEs), including heavy metals and metalloids, poses a significant public health risk in low- and middle-income countries (LMICs), where environmental surveillance is limited. This study assessed maternal and foetal exposure to PTEs in maternal and umbilical cord blood samples (n = 32 each) collected at Ishaka Adventist Hospital, Uganda, an agricultural region with known environmental contamination. Concentrations of arsenic (As), lead (Pb), chromium (Cr), nickel (Ni), copper (Cu), iron (Fe), and zinc (Zn) were quantified using Microwave Plasma Atomic Emission Spectroscopy; cadmium was undetected. Maternal samples had significantly higher mean concentrations than cord blood (p < 0.05), suggesting partial placental filtration. Nonetheless, maternal–foetal transfer ratios ranged from 10% (Zn) to 50.51% (Pb), indicating foetal exposure. Weighted Risk Score modelling revealed substantial maternal and foetal risks, primarily due to exposure to elevated levels of multiple metals (Pb, Ni, Cr and As). Spearman correlation and multivariate parsimonious regression analyses revealed significant associations between maternal and cord blood PTE concentrations and reported health issues. Notably, hypertension, respiratory allergies, gastrointestinal upsets, and gestational diabetes were correlated (singly or in combination) with higher maternal blood metal(loid) levels, passive smoking, geophagia, repeated use of mosquito coils, and use of biomass fuel (firewood), identifying these as potential environmental sources. Stratified Mann–Whitney and Kruskal–Wallis tests showed significantly higher Cr and Pb among mothers reporting geophagia, and significantly lower birth weight (LBW) among infants of older mothers and those practising geophagy. Similarly, cord blood metal(loid) levels were associated with LBW. Findings highlight substantial in utero exposure to a mixture of toxicants, with potential implications for adverse birth outcomes and long-term health effects, underscoring urgent maternal-child health interventions and environmental regulation in LMICs settings.